Oven-thermometer.



L. S. WHITE. A

v OVEN THERMOMETER.

APPLIOATION FILED JUNE 26, 1909.

Patented Nov. 30. 1909.

2 SHEETS-SHEET 1.

L. S. WHITE.

OVEN THERMOMETER. APPLICATION FILED JUNE 26, 1909.

Patented Nov. 30, 1909.

2 SHEETS-SHEET 2.

MW Q2 LEROY s. WHITE, or WATEKBURY, oonnncrrcur.

OVEN-THERMQMETER.

Specification of Letters Patent. Patented Nov, 30, 1909,

Application filed June 26, 1909. Serial No. 504,475.

To all whom it may concern:

Be it known that I, LEROY S. WHITE, a citizen of the United States, residing at Waterbury, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Oven-Thermometers; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description ofthe same, and which said drawings constitute part of this specification, and re resent, in-

Figure 1 a ront view of an oven thermometer embodying my invention. Fig. 2 a similar view with the dial. removed. Fig. 3 a vertical sectional view. Fig. 4 a broken transverse sectional view. Fig. 5 a front view of a modified form of my invention with the dial partially broken away. Fig. 6 a perspective view of a section of one form of expansible strip. Fig. 7 a perspective view of a section of another form of expansible strip.

This invention relates to an improvement in oven thermometers, .that is, a device mounted in an oven door and serving to indicate the approximate temperature of the oven, the object of the invention being a simple arrangement of parts which may be readily assembled, and which is comparatively thin so as to occupy but little space; and the invention consists in the construction hereinafter described and particularly reengagement with the threads of the opening 4 so as to form a tight joint with the plate2 and completely close the opening. Within the cup is the usual mechanism of an oven thermometeim This preferably consists of a three-armed yoke6 of such dimensions as to closely fit the interior of the cup so'that it will be held therein by friction. Two of the arms will be provided with outwardly extending lugs 7 which enter notches 8 formed in the dial 9, this dial being held in place by a ring 10 which supports a glass 11 which in turn is held in place by afriction collar 12 This plate has a central: threaded opening 4 toreceivea cup or shell 5 externally threaded at its inner end for fitting the outside of the dial and overlapping the outer edge of the glass.

As shown in Figs. 1, 2 and3 of the drawings the pointer 13 is mounted on a central shaft 14 carrying a pinion 15 which is in mesh with a segmental rack 16 mounted in the central arm 17. This rack is connected by a link 18 with one end of the metal strip' 19, the other end of which is connected with the yoke, the expansion and contraction of this strip moving the rack so as to turn the pointer.

Instead of having the pointer arranged in the center of the dial, it may be eccentrically mounted as shown in Fig. 5 of the drawings,

in which case the rack and pinion will be omitted, and the pointer mounted on a shaft 20 which carries a cam 21 corresponding to a portion of the rack.16 and to which the link 18 is connected. The strip 19 may be a bi-metal strip as shown .in'Fi 6 of the drawings, orit may consist 0 two independently formed strips 22 and 23 secured together by a series of rivets 24 as shown in Fig. 7 of the drawings, these being common forms of strips for oven thermometers as the action of heat on the different metals will cause the strip to straighten or bend so as to move the polnter in one direction or the other.

It will be noted that all tl're'mechanism is mounted in one cup or shell, and the closed end of that cup or shell closes the opening in the plate or flange which is provided to secure the thermometer to the oven door. I thus avoid all rivet holes in the case so that the possibility of leakage of steam or gases from the oven is avoided. The cup or shell may be threaded to a greater or less extent so as to be capable of being turned into the oven more or less as is required.

I claim I 1. In an oven thermometer, the combination with a cup the external side walls of which are threaded, of a flange adapted to be secured to the inner face of an oven door and formed with a threaded opening corresponding to the diameter of said cup which is adapted to be turned into it, an expansible strip mounted in the case and a pointer operated thereby.

2. In an oventhermometer, the combination with a plate or flange having a threaded opening, of a cup externally threaded at its inner end, a threearmed yoke friction- In testimony whereof, I have signed this ally held in said cup, :1 ointer mounted in specification in the presence of two subscrib- 10 said yoke, an expansib e strip connected ing witnesses.

with the yoke and with the pointer, said 5 oke formed with outwardly projecting WHITE ugs, and a dial having notches for e e- Witnesses: ment with said lug, and means for ho dmg S. J. WHITE,

the dial in position. E. L. Mm'rm. 

